1. Field of the Invention
The invention relates generally to a storage system and data management and migration method, and is suitable for use in a storage system where volumes have to be migrated between different types of storage apparatuses.
2. Description of Related Art
In storage systems handling a large amount of data, the data has been managed using large-capacity storage apparatuses provided separately from host systems.
The storage apparatuses used in these storage systems have many hard disk devices arranged in arrays and are configured so that the hard disk devices are used according to the RAID (Redundant Array of Independent Inexpensive Disks) system. These hard disk devices provide physical storage areas, for which at least one or more logical volumes (“logical volume(s)”) are set.
In these storage systems, when introducing a new storage apparatus or transferring the processing performed by a storage apparatus to another, clustered storage apparatus, the access destination for the host system has to be migrated to the newly-introduced storage apparatus or the other storage apparatus. In such cases, the migration of the access destination for the host system is ideally made without suspending the transmission of data between the host system and storage apparatuses.
A technique for changing an access target for a host system between storage apparatuses or volumes is disclosed in Japanese Patent Laid-Open Publication No. 2005-353035. A technique for migrating data between files is disclosed in Japanese Patent Laid-Open Publication No. 2006-164211.
However, with the existing methods for migrating the access destination for the host system to a new storage apparatus, there is a problem in that because cable replacement is required, the transmission of data between the host system and storage apparatuses has to be temporarily suspended.
Moreover, when migrating the access destination for the host system between different types of storage apparatuses (e.g., between an old-type storage apparatus and new-type storage apparatus made by the same vendor, or between storage apparatuses made by different vendors), it has been essential to change the micro program in the migration source storage apparatus, involving complex change processing for the migration.
This invention has been devised in light of these points and aims to propose a storage system and data management and migration method, with which an access destination for a host system can be migrated without having to stop the transmission of data between the host system and storage apparatuses.